The ERTS, ACCX, HR3, and P43S are compatible with with Shure, Line 6, and Sabine wireless systems only.  The ERTS, ACCX, and P43S include a hardwired cable which is not removable from the microphone.  The connector on the end of the cable is a TA4 wired in the Shure configuration.

The HR3 ships with a removable cable that includes a TA4 connector wired in the Shure configuration.   The HR3 can be used with Sennheiser wireless with the purchase of the optional AMT – Sennheiser cable.

The HR3 is also compatible with the AMT Wi5IIC wireless system.